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Wheel Width

Discussion in 'Wheels & Tires' started by htw9, Jul 4, 2010.

    • Member

    htw9

    Post Count: 9
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    I can get a set of Beyern rims with tires. But the width concerns me:

    18 x 8.5 front
    18 x 9.5 rear.

    That wider than the OEM wheels. The tire size match OEM. I'm concerned that the extra width may casue issues.

    Any comments?
    • Member

    az3579

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    Please specify the vehicle; nobody can give you advice if they don't know what car it is! :)
    • Member

    htw9

    Post Count: 9
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    Sorry - did the first post in a hurry. It's an '05 Z4 3.0
    • Member

    MGarrison

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    The Tire Rack (tirerack.com) shows 110 wheels in an 18" diameter for your car. The Rack shows BBS has an 18"x8.5 wheel with a +35mm offset & 6.22" backspacing to fit all 4 corners. It shows an Enkei wheel, 18"x8.5, +42mm offset, 6.37" backspacing for the front, & a rear 18"x9.5, +42mm offset, 6.92" backspacing.

    It shows some OZ wheels w/ 18x8.5" front fitments, but only 18"x9 rears.

    So check the offset & backspacing of the Beyerns. The Tire Rack won't sell a rim if it won't fit without a problem; if the Beyerns match the Enkei specs, you might be good to go. But, there could be other issues - you'd want to make sure the spokes clear the calipers.

    The Tire Rack doesn't show any wider tire size to fit than oem when using their 'shop by vehicle'. 225/40-18 front, 255/35-18 rear. If you're considering wider wheels, your rims will be better protected if the rims remain narrower than the tires. Apparently there is a fad ongoing of using rims wider than the tires - that's just asking for curb rash and bent or damaged rims if you ask me, I don't know why anyone would want that risk when putting that kind of money into their wheels. Point being, the typical performance advantage of opting for a wider rim is to improve 'handling' (ie, improved lateral grip) by allowing for useage of a wider tire without ballooning the sidewall; if a wider rim is used for the oem size tire, it might improve performance slightly by allowing for somewhat less sidewall flex. Adding rim width beyond the width of the tire is simply adding weight to the wheel/tire assembly, a performance detriment. Having rims wider than the tires is an aesthetic choice only, at the expense of practicality & performance.

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